
!function() {
	//封装方法，压缩之后减少文件大小

	function get_attribute(node, attr, default_value) {
		return node.getAttribute(attr) || default_value;
	}
	//封装方法，压缩之后减少文件大小

	function get_by_tagname(name) {
		return document.getElementsByTagName(name);
	}
	//获取配置参数

	function get_config_option() {
		var scripts = get_by_tagname("script"),
			script_len = scripts.length,
			script = scripts[script_len - 1]; //当前加载的script
		return {
			l: script_len,
			//长度，用于生成id用
			z: get_attribute(script, "zIndex", -99),
			//z-index
			o: get_attribute(script, "opacity", 0.8),
			//opacity
			c: get_attribute(script, "color", "0,133,161"),
			//color
			n: get_attribute(script, "count", 260) //count
		};
	}
	//设置canvas的高宽

	function set_canvas_size() {
		canvas_width = the_canvas.width = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth, canvas_height = the_canvas.height = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;
	}

	//绘制过程

	function draw_canvas() {
		context.clearRect(0, 0, canvas_width, canvas_height);
		//随机的线条和当前位置联合数组
		var e, i, d, x_dist, y_dist, dist; //临时节点
		//遍历处理每一个点
		random_points.forEach(function(r, idx) {
			r.x += r.xa, r.y += r.ya, //移动
			r.xa *= r.x > canvas_width || r.x < 0 ? -1 : 1, r.ya *= r.y > canvas_height || r.y < 0 ? -1 : 1, //碰到边界，反向反弹
			context.fillRect(r.x - 0.5, r.y - 0.5, 1, 1); //绘制一个宽高为1的点
			//从下一个点开始
			for (i = idx + 1; i < all_array.length; i++) {
				e = all_array[i];
				// 当前点存在
				if (null !== e.x && null !== e.y) {
					x_dist = r.x - e.x; //x轴距离 l
					y_dist = r.y - e.y; //y轴距离 n
					dist = x_dist * x_dist + y_dist * y_dist; //总距离, m

					dist < e.max && (e === current_point && dist >= e.max / 2 && (r.x -= 0.03 * x_dist, r.y -= 0.03 * y_dist), //靠近的时候加速
					d = (e.max - dist) / e.max, context.beginPath(), context.lineWidth = d / 2, context.strokeStyle = "rgba(" + config.c + "," + (d + 0.2) + ")", context.moveTo(r.x, r.y), context.lineTo(e.x, e.y), context.stroke());
				}
			}
		}), frame_func(draw_canvas);
	}
	//创建画布，并添加到body中
	var the_canvas = document.createElement("canvas"),
		//画布
		config = get_config_option(),
		//配置
		canvas_id = "c_n" + config.l,
		//canvas id
		context = the_canvas.getContext("2d"),
		canvas_width, canvas_height, frame_func = window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame ||
	function(func) {
		window.setTimeout(func, 1000 / 45);
	}, random = Math.random, current_point = {
		x: null,
		//当前鼠标x
		y: null,
		//当前鼠标y
		max: 20000 // 圈半径的平方
	}, all_array;
	the_canvas.id = canvas_id;
	the_canvas.style.cssText = "position:fixed;top:0;left:0;z-index:" + config.z + ";opacity:" + config.o;
	get_by_tagname("body")[0].appendChild(the_canvas);

	//初始化画布大小
	set_canvas_size();
	window.onresize = set_canvas_size;
	//当时鼠标位置存储，离开的时候，释放当前位置信息
	window.onmousemove = function(e) {
		e = e || window.event;
		current_point.x = e.clientX;
		current_point.y = e.clientY;
	}, window.onmouseout = function() {
		current_point.x = null;
		current_point.y = null;
	};
	//随机生成config.n条线位置信息
	for (var random_points = [], i = 0; config.n > i; i++) {
		var x = random() * canvas_width,
			//随机位置
			y = random() * canvas_height,
			xa = 2 * random() - 1,
			//随机运动方向
			ya = 2 * random() - 1;
		// 随机点
		random_points.push({
			x: x,
			y: y,
			xa: xa,
			ya: ya,
			max: 6000 //沾附距离
		});
	}
	all_array = random_points.concat([current_point]);
	//0.1秒后绘制
	setTimeout(function() {
		draw_canvas();
	}, 100);
}();
